I just explain to them that it is an internet money without physical form and you can trade with it like stocks. My family is not really into technology because we are from the province where internet connection is poor and the people living there have simple life. I am living now in the city and has good internet connection that's why I can easily access the sites but it is hard to explain to my family in detail because they are not interested in it. They just told me that as long as it is not scam then it's a good way of earning money.